Producing a profitable broiler requires that certain standards be met, some even before the chicks are placed on the farm and during the grow-out. The most important principle is to set the best quality fertile eggs in the machines and ensure that all eggs have been handled properly. It is preferred not to hold the eggs more than three days and the egg room must have the right temperature and humidity during storage to avoid killing or weakening the blastoderm. The longer the eggs are kept in storage the poorer the chick vigor, quality and hatch.
Optimum Egg Size
The most critical criteria are cleanliness of the eggs and minimum weight. The recommended minimum egg weight in the industry is 50 grams. In Table 1, egg weights related to breeder flock age are tabulated. If there is a shortage of hatching eggs, 45- to 50-gram eggs and even deformed eggs may be set, but they must be hatched separately and the chicks identified for more care at the farm.
There is no doubt that a direct relation exists between egg size and chick weight/quality. The larger the fertile egg, the larger the initial chick weight. The rule of thumb is that 68-72% of a small egg must be converted to chick, whereas 65-68% of a medium or large egg must be converted to chick. This can be achieved if the incubators and hatchers are working optimally.
The Farm Standards
At the farm, all house preparations must be completed prior to receiving chicks. Brooding temperatures that are too high may be more damaging to chicks than temperatures that are lower than optimal. During the first week of age, brooding temperature should not exceed 90°F (32°C) for whole-house brooding. High temperatures dehydrate the chicks and adversely affect their one-week body weight. It is well documented that a recently hatched chick is composed of 85% water. A chick becomes weak when it is dehydrated 10% and dies if it loses 20% of its body water. Food and water must be readily available to all chicks. If the chicks have been held for a long time at the hatchery or traveled long distances, it is suggested to provide them with water and sugar (4% solution) for the first couple of hours. The lost weight can be recuperated rapidly if water is readily available. If all goes well, a chick should weigh 4.5 times its original day-of-age weight at 1 week of age. Well-managed farms commonly report that chicks weigh 5 times their original arrival weight. How to achieve this depends on some very basic factors:
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Good state of health.
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Excellent chick quality.
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Sufficient feeder and water space.
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Adequate brooding area. If possible avoid making rings and practice partial brooding for the first 21 days.
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Plenty of fresh air at the chick level from time of arrival.
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Good quality feed with proper texture. If possible feed the chicks with chick-size crumble feed. Crumble feed has gone through high temperatures and is more likely to be free of contaminants such as Salmonella spp. Crumble feed also encourages feed consumption and less feed wastage. A broiler chick must consume at least 170 grams of feed during the first seven days. All efforts must be made to achieve this goal. If this amount is consumed the first week, the broiler will have a good size frame and can grow to its potential.
Broiler Weekly Body Weight and Average Daily Weight Gains
The rule of thumb for average straight run broilers is outlined in Table 2: The average gram daily weight gains play an important role in the optimum growth of the birds. Under normal practical conditions, a broiler must gain an average of 65 grams or more per day. The average daily weight gain is not uniform for each week and varies considerably depending on age and sex. Table 3 demonstrates the daily gains from 1 to 49 days on a weekly interval basis for straight run broilers.
Hatchery Numbers
Malpositions and Deformities
Malpositions and deformities incidences in a normal hatch of 86%. Refer to Tables 4 and 5.
The number of embryos unable to hatch due to malpositions usually ranges from 0.8% to 1.2% and should not exceed 1%
The number of embryos that develop deformities ranges from 0.05% to 0.10% and should not exceed 0.10%.
Hatchability of Undergrade Eggs
Normally, the percentage of cull fertile eggs should not exceed 4.0%. If market demand for fertile eggs is great, culls can be lowered to 2.5%–3.0% by decreasing cracks, saving mildly deformed and porous eggs, and reducing minimum egg weights for incubation. Refer to tables 6 and 7.
Broiler Performance from Cull Eggs
Refer to Tables 8 and 9.
Specific Gravity Technique
1. Between 3 and 5 solutions needed, confirm with hydrometer, leave in egg holding room, allow eggs to cool to holding room temperature.
1.070
1.075 0.9lbs salt/gallon water
1.080 1.0lbs salt/gallon water
1.085 1.025lbs/gallon water
1.090
2. First put the eggs in a 1.075 solution of water and salt. Remove those that float and take to next solution—1.080, 1.085, etc.
3. Calculate % in each category.
Embryodiagnosis
Ideally embryodiagnosis involes two steps: ovoscopy and then breakout of residue from the same eggs.
1. Evaluate 3 trays from each breeder farm on a weekly basis.
2. Data sheets should include: ID of breeder flock, age of flock, breed cross, health status, type of machine, storage duration and location of tray in hatcher. On each sheet, record the following:
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% hatch for lot
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% hatch for selected trays
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Total eggs/tray
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Number of healthy chicks
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Number of dead chicks
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Number of second quality chicks
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Number of exploders
3. Collect pips, unhatched eggs, and dead chicks and put in flats. Then do the following:
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Count pips, remove shell and ID malposition.
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Open remaining eggs and ID the infertile ones. For the rest, determine time of death.
Key Developmental Features
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7–8 days: eyes can be distinguished
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13–14 days: feathers have started to develop
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15 days: all structures have formed
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Peak fertility: 97%
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Peak hatch of fertiles: 93.5%
